CBuffer.h

00001 /* Copyright (C) 2012 mbed.org, MIT License
00002  *
00003  * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
00004  * and associated documentation files (the "Software"), to deal in the Software without restriction,
00005  * including without limitation the rights to use, copy, modify, merge, publish, distribute,
00006  * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
00007  * furnished to do so, subject to the following conditions:
00008  *
00009  * The above copyright notice and this permission notice shall be included in all copies or
00010  * substantial portions of the Software.
00011  *
00012  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
00013  * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
00014  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
00015  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00016  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
00017  */
00018 
00019 #ifndef CIRCBUFFER_H_
00020 #define CIRCBUFFER_H_
00021 
00022 template <class T>
00023 class CircBuffer {
00024 public:
00025     CircBuffer(int length) {
00026         write = 0;
00027         read = 0;
00028         size = length + 1;
00029         buf = (T *)malloc(size * sizeof(T));
00030     };
00031 
00032     bool isFull() {
00033         return (((write + 1) % size) == read);
00034     };
00035 
00036     bool isEmpty() {
00037         return (read == write);
00038     };
00039 
00040     void queue(T k) {
00041         if (isFull()) {
00042             read++;
00043             read %= size;
00044         }
00045         buf[write++] = k;
00046         write %= size;
00047     }
00048     
00049     void flush() {
00050         read = 0;
00051         write = 0;
00052     }
00053     
00054 
00055     uint32_t available() {
00056         return (write >= read) ? write - read : size - read + write;
00057     };
00058 
00059     bool dequeue(T * c) {
00060         bool empty = isEmpty();
00061         if (!empty) {
00062             *c = buf[read++];
00063             read %= size;
00064         }
00065         return(!empty);
00066     };
00067 
00068 private:
00069     volatile uint32_t write;
00070     volatile uint32_t read;
00071     uint32_t size;
00072     T * buf;
00073 };
00074 
00075 #endif